Method and apparatus for enhancing the power efficiency of wireless communication devices

ABSTRACT

Method and system for enhancing the power efficiency of a first wireless device that includes an energy receiver. In one implementation, the method includes receiving a transmitted signal at the first wireless device, converting the transmitted signal into power through the energy receiver, and providing the power to the first wireless device.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.11/857,655, filed Sep. 19, 2007, the entire contents of which areincorporated herein by reference.

FIELD OF THE INVENTION

This disclosure relates generally to electrical circuits, and moreparticularly to techniques for enhancing the power efficiency of awireless communication device (referred to herein as “wireless device”).

BACKGROUND OF THE INVENTION

FIG. 1 illustrates a conventional wireless communication system 100including wireless devices 102, 104. The wireless device 102 includes aDC power source 106 that provides power to a transmit processor 108, amodulator 110, and a power amplifier 112. The wireless device 102further includes (optional) regulators 114, 116, 118 that respectivelyprovide a correct voltage and/or current regulation to the transmitprocessor 108, the modulator 110, and the power amplifier 112. Inoperation, a transmit frequency (TX Fc, Fc(s)) of the transmit processor108 is typically set to a specific frequency associated a wirelesscommunication standard—e.g., GSM (global system for mobilecommunications), wireless LAN (local area network), Bluetooth, and thelike. For example, the modulator 110 can comprise a voltage controlledoscillator and phase lock loop to select a given transmit frequency froma range of possible transmit frequencies. The power amplifier 112amplifies a power of a modulated signal output from the modulator 110,and the output of the power amplifier 112 (referred to in the followingFigs. as “TX Signal Power(s))” is transmitted through a transmit antenna120 into free space. A receiver 122 of the wireless device 104 receivesthe radiated signal through a receive antenna 124 and processes theradiated signal, thus allowing wireless communication of informationbetween the wireless device 102 and the wireless device 104.

In general, because wireless devices are not connected through aphysical wire, signals that are transmitted from a wireless device aretypically attenuated (reduced) and/or distorted due to travel in freespace. Therefore, as a distance D_(L)(s) (ranging from, e.g., 0 miles tomillions of miles) increases between the wireless device 102 and thewireless device 104, an amount of attenuation and/or distortion ofsignals transmitted from the wireless device 102 to the wireless device104 also increases. For example, a GSM cellular phone can transmit asignal having a power that averages 1-2 Watts, however, a GSM receivertypically receives a signal having a power as small as 60×10-12Watts—most of the signal power is lost in free space. Attenuation and/ordistortion of a signal can cause an amplitude of a signal to be too lowor too distorted for correction by the wireless device 104.

SUMMARY OF THE INVENTION

In general, this specification describes a method for enhancing thepower efficiency of a first wireless device that includes an energyreceiver. The method includes receiving a transmitted signal at thefirst wireless device, converting the transmitted signal into powerthrough the energy receiver, and providing the power to the firstwireless device.

Implementations can include one or more of the following features. Thetransmitted signal can be a time variant signal having a pre-determinedfrequency, and converting the transmitted signal into power can includesetting a frequency of the energy receiver substantially to thepre-determined frequency of the time variant signal. Setting thefrequency of the energy receiver substantially to the pre-determinedfrequency of the time variant signal can include calibrating the energyreceiver to substantially match the pre-determined frequency of the timevariant signal using one or more pre-calibrated control signal values.The pre-determined frequency can be associated with one or more wirelesscommunication standards selected from the group of GSM, CDMA, WCDMA,Bluetooth, or IEEE 802.11. Converting the transmitted signal into powercan further include converting AC power associated with the time variantsignal into DC power through an AC to DC converter. The transmittedsignal can be a signal having been transmitted from the first wirelessdevice. Converting the transmitted signal into power through the energyreceiver can include determining an AC power associated with the signalthrough an electrical coupling of the energy receiver and a transmitterof the first wireless device. The electrical coupling between the energyreceiver and the transmitter can be formed using one or more inductors,capacitors, wires, or traces. The transmitted signal can be a signalhaving been transmitted from a second wireless device that is separatefrom the first wireless device. The second wireless device cancommunicate in accordance with a different wireless communicationstandard than the first wireless device.

The first wireless device can be one of a cellular phone, a wirelessheadset, a personal digital assistant (PDA), a laptop or desktopcomputer, a router, or a key fob. The first wireless device can furtherinclude an electrical shield to absorb electromagnetic interference(EMI), and the method can further include converting the electromagneticinterference (EMI) absorbed through the electrical shield into powerthrough the energy receiver. Converting the transmitted signal caninclude setting a frequency of the energy receiver substantially to acentered frequency of a pre-determined frequency range. Providing thepower to the first wireless device can include providing the power to acomponent of the first wireless device. The component can be one of atouch pad, a light, a display screen, a digital signal processor, areceiver, a transmitter, or a battery.

In general, in another aspect, this specification describes a wirelessdevice. The wireless device includes a transmitter to transmit a signalfrom the wireless device, and an energy receiver to converting thesignal transmitted from the transmitter into power and provide the powerto a component of the wireless device.

Particular implementations can include one or more of the followingfeatures. The signal transmitted from the transmitter can be a timevariant signal having a pre-determined frequency, and the wirelessdevice can further include a control circuit to set a frequency of theenergy receiver to the pre-determined frequency of the time variantsignal. The control circuit can be configured to set the frequency ofthe energy receiver to the pre-determined frequency of the time variantsignal using one or more pre-calibrated control signal values. Theenergy receiver can further include an AC to DC converter to convert ACpower associated with the time variant signal into DC power.

The details of one or more implementations are set forth in theaccompanying drawings and the description below. Other features andadvantages will be apparent from the description and drawings, and fromthe claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a conventional wireless communicationsystem.

FIG. 2 is a block diagram of a wireless communication system includingan energy receiver in accordance with one implementation.

FIG. 3 depicts a method for enhancing the power efficiency of a wirelessdevice using an energy receiver in accordance with one implementation.

FIG. 4 is a block diagram of a wireless communication system includingan energy receiver in accordance with one implementation.

FIG. 5 is a block diagram of a wireless communication system includingan energy receiver in accordance with one implementation.

FIG. 6 is a block diagram of a wireless communication system includingan energy receiver in accordance with one implementation.

FIG. 7 depicts a calibration algorithm for determining peak power of areceived signal in accordance with one implementation.

FIG. 8 is a block diagram of a wireless communication system includingan energy receiver in accordance with one implementation.

FIG. 9 depicts a method of operation for an energy receiver inprocessing received signals in accordance with one implementation.

FIG. 10 is a block diagram of a wireless communication system includingan energy receiver in accordance with one implementation.

FIG. 11 depicts a method of operation for an energy receiver inprocessing received signals in accordance with one implementation.

FIG. 12 is a block diagram of an energy receiver in accordance with oneimplementation.

FIG. 13 is a block diagram of multiple energy receivers sharing the sameAC to DC converter in accordance with one implementation.

FIG. 14 is a block diagram of an energy receiver coupled to electricalshielding in accordance with one implementation.

FIG. 15 is a block diagram of a data processing system in accordancewith one implementation.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION OF THE INVENTION

This disclosure relates generally to electrical circuits, and moreparticularly to techniques for enhancing the power efficiency of awireless communication device. The following description is presented toenable one of ordinary skill in the art to make and use the inventionand is provided in the context of a patent application and itsrequirements. The present invention is not intended to be limited to theimplementations shown but is to be accorded the widest scope consistentwith the principles and features described herein.

FIG. 2 illustrates one implementation of a wireless communication system200 including wireless devices 202, 204. The wireless devices 202, 204can be any type of device operable to transmit a signal wirelessly—e.g.,a cellular phone, a personal digital assistant (PDA), a wirelessheadset, a laptop or desktop computer, a router, a key fob, and thelike. In one implementation, the wireless device 202 includes atransmitter 206 and an energy receiver 208. In one implementation, theenergy receiver 208 converts a signal (transmitted from transmitter 206to the wireless device 204) into power that is then provided back to,e.g., the transmitter 206 and/or another component 210 of the wirelessdevice 202. The component 210 can be any function associated with thewireless device that requires power—e.g., a touch pad, a light (orbacklight), a display screen, a digital signal processor, a receiver, atransmitter, a battery, and so on. In one implementation, the signalthat is converted into power is a time variant (or AC) communicationsignal. Although the wireless device 202 is shown as including onetransmitter and one energy receiver, the wireless device 202 can includeany number of transmitters and energy receivers. The wireless device 204can include a transmitter and an energy receiver (not shown). In oneimplementation, the energy receiver 208 is further operable to convert asignal transmitted from the wireless device 204 into power for use bythe wireless device 202. In such an implementation, the wireless device202 can receive power from the energy receiver 208 even when thetransmitter 206 is not active.

Thus, the additional power provided by the energy receiver 208 can beused as a supplementary power source to a battery or other power sourcewithin the wireless device 202. In one implementation, the energyreceiver 208 is frequency matched to a frequency of a transmitted signalto increase effectiveness of the energy receiver 208 so that the energyreceiver 208 can capture a maximum amount of power from the transmittedsignal.

FIG. 3 illustrates a method 300 for enhancing the power efficiency of awireless device (e.g., wireless device 202) using an energy receiver inaccordance with one implementation. A transmitted signal is received atthe wireless device (step 302). In one implementation, the transmittedsignal is a signal that was transmitted by the wireless device. In oneimplementation, the transmitted signal is a signal that was transmittedfrom a second device (e.g., wireless device 204) that is separate fromthe wireless device. In one implementation, the transmitted signal is atime variant communication signal. In one implementation, the timevariant communication signal is a modulated signal having a specificfrequency associated a wireless communication standard (e.g., GSM, CDMA(code division multiple access), WCDMA (wideband code division multipleaccess), Bluetooth, IEEE 802.11, and the like). The transmitted signalis converted into power (e.g., by the energy receiver) (step 304). Inone implementation, the energy receiver includes an AC to DC converterto convert AC power from the transmitted signal into DC power. The poweris provided to a component of the wireless device (step 306). Asdiscussed above, the component can be any function associated with thewireless device that requires power. Generally, the power can be used topower functions or circuits within the wireless device, for example, theadditional power can be used to charge (or extend the life of) a batterywithin the wireless device.

FIG. 4 illustrates one implementation of a wireless communication system400 including wireless devices 402, 404. In one implementation, thewireless device 402 includes a DC power source 406 that provides powerto a transmit processor 408, a modulator 410, and a power amplifier 412.In one implementation, the wireless device 402 further optionallyincludes regulators 414, 416, 418 that respectively provide a correctvoltage and/or current regulation to the transmit processor 408, themodulator 410, and the power amplifier 412. In one implementation, theDC power source 406 further provides power to a component 436 of thewireless device 202. The component 436 can be, for example, a touch pad,a light (or backlight), a display screen, a digital signal processor, areceiver, a transmitter, a battery, and so on. In one implementation,the wireless device 402 further includes an energy receiver 420 thatincludes an energy receiver (ERX) circuit 422 to receive a time variantcommunication signal and an AC to DC converter 424 to convert thereceived communication signal into DC power. The energy receiver 420 canfurther include a DC power management circuit 426 that can provideproper voltage levels of DC power to circuits (or components) within thewireless devices 402.

In one implementation, a distance (D_(S)(s)) between an antenna 428 andan antenna 430 (of the energy receiver 420) is much smaller relative toa distance (D_(L)(s)) between the antenna 428 and an antenna 432 (of areceiver 434 within the wireless device 404). In such an implementation,the antenna 430 (and energy receiver circuit 422) can be placedphysically near the antenna 428 by design intention. Therefore, theenergy receiver 420 can receive a signal transmitted from the antenna428 having less attenuation and/or distortion compared a signal receivedby the antenna 432 of the wireless device 404. Operating characteristicsassociated with the (transmitter) antenna 428 and signals transmitted bythe antenna 428 can be known at a time of manufacture and, therefore,during manufacture, a design of the antenna 430 of the energy receiver420 can optimized to capture a maximum amount of signal transmittedthrough the antenna 428. The antenna 430 of the energy receiver 420 andother components of the energy receiver 420 can be designed and placedso as to not interfere with signals radiated to an intended remotewireless device antenna (e.g., antenna 432 of the wireless device 404).

FIG. 5 illustrates one implementation of the wireless communicationsystem 400 further including a wireless device 502. As shown in FIG. 5,the wireless device 502 includes a transmitter 504 and an antenna 506that is a distance D_(M)(s) away from the antenna 430 of the energyreceiver 420. In the implementation shown in FIG. 5, the energy receiver420 is configured to also convert a transmitted signal from the wirelessdevice 502 into DC power for use by the wireless device 402. Thetransmitted signal from the wireless device 502 can be a time variantsignal associated with a same or different wireless communicationstandard as a signal transmitted by the wireless device 402.

FIG. 6 illustrates one implementation of a wireless communication system600 including wireless devices 602, 604. The wireless device 602includes an energy receiver 606. Each of the wireless devices 602, 604include components similar to the wireless devices discussed above. Inthe implementation, of FIG. 6, the ERX Circuitry Element(s) (or energyreceiver circuit) is set to the same (or nearly the same) frequency asthat of the signal transmitted from a transmit antenna (TX Antenna(s))of the wireless device 602. In one implementation, the frequency of theERX Circuitry Element(s) is set based on a control signal—TX Fc or Fc(s)Control Signal(s). In one implementation, the energy receiver 606includes a DC Power Measure circuit configured to measure a value of theERX DC Power output from the AC to DC converter and an ERX Element(s)Calibration Control circuit uses the ERX DC Power measurement value tocalibrate a frequency of the ERX Circuitry Element(s) so that thefrequency substantially matches a frequency of a signal transmitted froma transmit antenna (TX Antenna(s)) of the wireless device 602.

During manufacture of a wireless device (e.g., wireless device 602), ERXCircuitry Element(s) may have component tolerance errors such that anenergy receiver cannot achieve (or operate at) the same frequency as thefrequency of a transmitted signal. If the frequency of the energyreceiver does not match the frequency of a transmitted signal, theenergy receiver may receive none or less than a maximum attainableamount of a transmitted signal. Thus, by adding an ERX Element(s)Calibration Control Circuit and corresponding calibration algorithm(discussed below in connection with FIG. 7), ERX Circuitry Element(s)within the energy receiver 606 can be made to match the frequency of atransmitted signal; therefore, the frequency of the energy receiver willlie within a transmit (TX) Signal Power Spectral Envelope; hence amaximum possible amount of a transmitted signal can be received by theenergy receiver 606. For example, according to the graph 608 shown inFIG. 6, if the ERX Fc1 or Fc1(s) (the frequency of the energy receiver)lies within the TX Signal Power(s) Spectral Envelope, a maximum possibleTX Signal Power(s) can be received; if the ERX Fc2 or Fc2(s) liespartially within the TX Signal Power(s) Spectral Envelope, less than amaximum possible TX Signal Power(s) can be received; and if ERX Fc3 orFc3(s) lies outside of the TX Signal Power(s) Spectral Envelope, no TXSignal Power(s) can be received.

FIG. 7 illustrates one implementation of a calibration algorithm 700that can be implemented to calibrate ERX Circuitry Element(s) within anenergy receiver so that the frequency of the energy receiver can matchthe frequency of a signal transmitted from a transmitter of a wirelessdevice. A transmitter signal is set to a pre-determined transmitfrequency (Fc1 or Fc1(s) (step 702). Power level values in thetransmitter signal are set to nominal values (step 704). The energyreceiver is set to the pre-determined transmit frequency (Fc1 or Fc1(s)(step 706). The calibration control signal(s) of the energy receiver areset to initial values (step 708). A measurement of the ERX DC Power isperformed (e.g., through DC Power Measure circuit of FIG. 6) (step 710).A determination is made whether the ERX DC Power is stable (step 712).If the ERX DC Power is not stable, the DC Power Measure circuit waitsfor a pre-determined amount of time before measuring a value of the ERXDC Power (step 714). If the ERX DC Power is stable, a determination ismade whether a peak DC power level has been achieved (step 716). If thepeak DC power level has not been achieved, the calibration controlsignal(s) of the energy receiver are incremented (step 718) and thealgorithm 700 returns to step 710 to measure the ERX DC Power. If thepeak DC power level has been achieved, then values of the calibrationcontrol signal(s) of the energy receiver are stored for use duringoperation.

The calibration algorithm 700 can be repeated for any transmit frequencyFc or Fc(s), and the calibration algorithm 700 can be repeated formultiple transmitters in the same wireless device. Thus, if a frequencyof an energy receiver (ERX Fc or Fc(s)) does not match a transmitfrequency (TX Fc or Fc(s)) of a transmitter, then the calibrationalgorithm 700 will ensure the correct Calibration Control Signal(s)Value(s) can be found and applied to ensure maximum received ERX DCPower.

FIG. 8 illustrates one implementation of a wireless communication system800 including wireless devices 802, 804. In the wireless communicationsystem 800, the transmitter of wireless devices 802 is inactive. In sucha case, then the ERX Circuitry Element(s) can be set to the center ofits own TX Frequency Range Fc_center or Fc(s)_center, with the ERXElement(s) Calibration Control Signal(s) Value(s) set for peak power.This will allow the energy receiver to receive a signal transmitted froma transmitter of another similar wireless device (e.g., wireless device804). The received signal can be converted to DC Power to supply powerto a component of the wireless device 802 having an inactive transmitter(or no transmitter).

Wireless communication standards generally occupy specific transmit (TX)frequency ranges, and a wireless device is likely to exist in anenvironment where other wireless devices employ the same and/or similarwireless communication standard. In such circumstances, this increasesthe probability of an energy receiver being able to receive signalstransmitted from other wireless devices of the same and/or similarwireless communication standards. Thus, by setting the ERX CircuitryElement(s) to a TX Frequency Range Center and setting the ERX Element(s)Calibration Control Signal(s) to peak power value(s), the ERX will liein the center of TX Signal Power(s) Spectral Envelope and, therefore,allow for increased probability of receiving a transmitted signal fromother wireless devices. Such an approach possibly permits an energyreceiver to receive signals transmitted from wireless devices operatingin accordance with a different wireless communication standard. Forexample, as shown in the graph 806 of FIG. 8, the ERX Fc_center or Fc1(sLcenter lies at the center of a TX Signal Power(s) Spectral Envelopefor a given wireless communication standard. Alternatively, the ERXElement(s) TX Fc or Fc(s) Control Signal(s) and/or ERX Element(s)Control Signal(s) may be deliberately set to match and be calibrated toa frequency of signal transmitted by a nearby wireless device. The TX Fcor Fc(s) information can also be wirelessly transmitted to ERXElement(s) (as discussed in greater detail below).

FIG. 9 depicts a method 900 for setting a frequency of an energyreceiver within a wireless device in accordance with one implementation.A determination is made whether a transmitter (e.g., within the samewireless device as the energy receiver) is active (step 902). If thetransmitter is active, a frequency of ERX Circuitry Element(s) withinthe energy receiver is set to a same frequency as that of thetransmitter (Fc1 or Fc1(s)) (e.g., by a functional circuit within theenergy receiver) (step 904). One or more values of the calibrationcontrol signal(s) within the ERX Circuitry Element(s) are set for peakpower (e.g., by an ERX Element(s) Calibration Control circuit) (step906). Signal(s) transmitted by the transmitter is then received by theERX Circuitry Element(s) (step 908). If, however, the transmitter withinthe same wireless device as the energy receiver is not active, afrequency of ERX Circuitry Element(s) within the energy receiver is setto a TX Frequency Range Center—Fc_center or Fc1(s)_center (e.g., by afunctional circuit within the energy receiver) (step 910). One or morevalues of the calibration control signal(s) within the ERX CircuitryElement(s) are set for peak power (e.g., by an ERX Element(s)Calibration Control circuit) (step 912). Signal(s) transmitted by one ormore transmitter(s) that are not within the same wireless device as theenergy receiver are then received by the ERX Circuitry Element(s) (step914).

FIG. 10 illustrates one implementation of a wireless communicationsystem 1000 including wireless devices 1002, 1004. In the implementationshown in FIG. 10, the wireless device 1002 includes an energy receiverthat is calibrated to match a transmit frequency of a transmitter withinthe wireless device 1004. In such a case, a signal transmitted from thewireless device 1004 may have a larger power relative to a signaltransmitted from the wireless device 1002. Thus, ERX Element(s) TX Fc orFc(s) Control Signal(s) and/or ERX Element(s) Control Signal(s) withinan energy receiver may be deliberately set to match and be calibrated toa frequency of a transmitted signal (TX Signal Power(s)) of one or morenearby wireless devices (e.g., wireless device 1004). In oneimplementation, the transmit frequency information (TX Fc or Fc(s))associated with nearby wireless devices can be wirelessly Transmitted toERX Element(s) within the energy receiver of the wireless device 1002.

Accordingly, in a case in which a first wireless device generates asmall amount of TX Signal Power(s) relative to the TX Signal Power(s) ofa second wireless device, it may be more advantageous to have an energyreceiver (ERX) within the first wireless device set and calibrated toreceive signals transmitted from the second wireless device. Forexample, Bluetooth devices (2.4 GHz TX Frequencies) typically have anaverage TX Signal Power of 1×10-3 Watt, 2.5×10-3 Watt, or 100×10-3 Watt,and cellular phone (800, 900, 1800, 1900 MHz TX Frequencies) typicallyhave an average TX Signal Power of 1 Watt, 2 Watts, 5 Watts or more. Ifan energy receiver within a Bluetooth device is set and calibrated toreceive TX Signal Power(s) of a nearby cellular phone, the energyreceiver will be able to generate a larger amount of DC power from areceived signal than if the energy receiver were set and calibrated to atransmit frequency of a Bluetooth device. For example, as shown in thegraph 1006 of FIG. 10, if the ERX Fc1 or Fc1(s) lies within the TXSignal Power(s) Spectral Envelope of a nearby transmitter, a maximumamount of nearby TX Signal Power(s) can be received; if ERX Fc2 orFc2(s) lies partially within the TX Signal Power(s) Spectral Envelope ofa nearby transmitter, less than a maximum amount of nearby TX SignalPower(s) is attainable; and if ERX Fc3 or Fc3(s) lies outside the TXSignal Power(s) Spectral Envelope of a nearby transmitter, no nearby TXSignal Power(s) can be received. Alternatively, ERX Element(s) TX Fc orFc(s) Control Signal(s) and/or ERX Element(s) Control Signal(s) may bedeliberately set to match and be calibrated to TX Frequency RangeFc_center or Fc(s)_center of nearby wireless device(s), as discussedabove.

FIG. 11 depicts a method 1100 for setting a frequency of an energyreceiver within a wireless device in accordance with one implementation.A determination is made whether a power of a signal transmitted by atransmitter (e.g., within the same wireless device as the energyreceiver) is lower than a power of a signal transmitted by anothertransmitter (e.g., a nearby transmitter) (step 1102). If the power of asignal transmitted by the transmitter (within the same wireless deviceas the energy receiver) is greater than the power of a signaltransmitted by another transmitter, a frequency of ERX CircuitryElement(s) within the energy receiver is set to a same frequency as thatof the transmitter (Fc1 or Fc1(s)) (e.g., by a functional circuit withinthe energy receiver) (step 1104). One or more values of the calibrationcontrol signal(s) within the ERX Circuitry Element(s) are set for peakpower (e.g., by an ERX Element(s) Calibration Control circuit) (step1106). Signal(s) transmitted by the transmitter is then received by theERX Circuitry Element(s) (step 1108).

If, however, the power of a signal transmitted by the transmitter(within the same wireless device as the energy receiver) is not greaterthan the power of a signal transmitted by another transmitter, afrequency of ERX Circuitry Element(s) within the energy receiver is setto a same frequency as that of the other transmitter (Fc1 or Fc1(s))(e.g., by a functional circuit within the energy receiver) (step 1110).One or more values of the calibration control signal(s) within the ERXCircuitry Element(s) are set for peak power (e.g., by an ERX Element(s)Calibration Control circuit) (step 1112). One or more signalstransmitted by the other transmitter (not within the same wirelessdevice as the energy receiver) are then received by the ERX CircuitryElement(s) (step 1114).

FIG. 12 illustrates one implementation of an energy receiver 1200. Inone implementation, the energy receiver can receive AC power though anelectrical coupling between electrical components such as, for example,inductors, capacitors, wires, traces, and the like without having toreceive a signal transmitted through an antenna. Thus, manufacture of agiven wireless device, electrical components can be made to maximize theeffect of coupling through careful design—e.g., components, wires,traces can be placed very close to each other to increase an electricalcoupling effect—to maximize received AC electrical power. Further, FIG.13 illustrates another implementation of an energy receiver 1300 inwhich multiple ERX elements can share a same AC to DC converter.

FIG. 14 illustrates one implementation of an energy receiver 1400including ERX Circuitry Element(s) that is further coupled to electricalshielding. Conventionally, electrical shielding is typically used todissipate electrical energy (e.g., electromagnetic interference (EMI))to ground. However, in the implementation shown in FIG. 14, the ERXCircuitry Element(s) within the energy receiver 1400 is configured toconvert AC electrical energy absorbed by the electrical shielding intoDC power for use by components within a wireless device.

One or more of method/algorithm steps described above can be performedby one or more programmable processors executing a computer program toperform functions by operating on input data and generating output.Generally, the invention can take the form of an entirely hardwareembodiment, an entirely software embodiment or an embodiment containingboth hardware and software elements. In one implementation, theinvention is implemented in software, which includes but is not limitedto firmware, resident software, microcode, etc. Furthermore, theinvention can take the form of a computer program product accessiblefrom a computer-usable or computer-readable medium providing programcode for use by or in connection with a computer or any instructionexecution system. For the purposes of this description, acomputer-usable or computer readable medium can be any apparatus thatcan contain, store, communicate, propagate, or transport the program foruse by or in connection with the instruction execution system,apparatus, or device. The medium can be an electronic, magnetic,optical, electromagnetic, infrared, or semiconductor system (orapparatus or device) or a propagation medium. Examples of acomputer-readable medium include a semiconductor or solid state memory,magnetic tape, a removable computer diskette, a random access memory(RAM), a read-only memory (ROM), a rigid magnetic disk and an opticaldisk. Current examples of optical disks include compact disk—read onlymemory (CD-ROM), compact disk—read/write (CD-R/W) and DVD.

FIG. 15 illustrates a data processing system 1500 suitable for storingand/or executing program code. Data processing system 1500 includes aprocessor 1502 coupled to memory elements 1504A-B through a system bus1506. In other implementations, data processing system 1500 may includemore than one processor and each processor may be coupled directly orindirectly to one or more memory elements through a system bus. Memoryelements 1504A-B can include local memory employed during actualexecution of the program code, bulk storage, and cache memories thatprovide temporary storage of at least some program code in order toreduce the number of times the code must be retrieved from bulk storageduring execution. As shown, input/output or I/O devices 1508A-B(including, but not limited to, keyboards, displays, pointing devices,etc.) are coupled to data processing system 1500. I/O devices 1508A-Bmay be coupled to data processing system 1500 directly or indirectlythrough intervening I/O controllers (not shown).

Various implementations for enhancing the power efficiency of a wirelesscommunication device have been described. Nevertheless, variousmodifications may be made to the implementations. For example, thoughthe techniques described above refer to wireless devices, the techniquesare applicable to wired devices (including devices that can be connectedto an electrical outlet). In addition, steps of the methods/algorithmsdescribed above can be performed in a different order and still achievedesirable results. Accordingly, many modifications may be made withoutdeparting from the scope of the following claims.

What is claimed is:
 1. A wireless device comprising: a transmitter totransmit a signal at a pre-determined frequency; an energy receiverconfigured to receive a signal at the pre-determined frequency includinga portion of the signal transmitted from the transmitter, convert theportion of the signal transmitted from the transmitter into power, andprovide the power to a component of the wireless device; and a controlcircuit to set a frequency of the energy receiver to the pre-determinedfrequency, wherein a distance between the transmitter and the energyreceiver is fixed.
 2. The wireless device of claim 1, wherein thecontrol circuit is configured to set the frequency of the energyreceiver to the pre-determined frequency using one or morepre-calibrated control signal values.
 3. The wireless device of claim 1,further comprising: an AC to DC converter to convert AC power associatedwith the transmitted signal received by the energy receiver into DCpower.
 4. The wireless device of claim 1, wherein the wireless device isone of a cellular phone, a wireless networking device, a wirelessheadset, a personal digital assistant (PDA), a laptop or desktopcomputer, a router, or a key fob.
 5. The wireless device of claim 1,wherein the component is one of a touch pad, a light, a display screen,a digital signal processor, a receiver, a transmitter, or a battery. 6.The wireless device of claim 1, wherein the component is a power supplythat is charged with the power provided thereto.
 7. The wireless deviceof claim 1, wherein the pre-determined frequency is associated with oneor more wireless communication standards selected from the group of GSM,CDMA, WCDMA, Bluetooth, or IEEE 802.11.
 8. The wireless device of claim1, further comprising: an electrical shield to absorb electromagneticinterference (EMI).